All-ceramic Bridge Research Articles

Effects of porcelain veneering methods on conformity of the marginal and internal fit of three-unit zirconia framework.

The purpose of this study is to investigate the effects of porcelain veneering methods on the marginal and internal fit of a three-unit zirconia framework. A zirconia master model, in which the lower-left second premolar and the second left molar were used as the abutment, was obtained using an intraoral scanner. Based on the data, three-unit zirconia frameworks for fabricating all-ceramic bridges were designed and milled (FW group). Two types of all-ceramic bridge were fabricated by veneering porcelain onto these frameworks using the press-over technique (P group) and the layering technique (L group). The replica technique was used to measure the gap size between the abutments and the bridges. Measurements were taken in the marginal opening area (MO), chamfer area (CH), axial area (AX), and occlusal area (OC). Statistical analysis was performed using the Mann-Whitney U-test. There was no significant difference in MO and CH between the P and L groups. However, in AX, the L group had a significantly larger gap size than that of the P group (p = 0.003). In addition, compared with the FW group, the P group showed a significantly larger gap size in MO (p < 0.000), CH (p = 0.008), and OC (p < 0.000). These results indicate that the gap size increased after porcelain veneering using the press-over and layering techniques. In addition, the all-ceramic bridges fabricated using the press-over and layering techniques had approximately equal gap sizes in MO.

Aesthetic rehabilitation in a patient with skeletal mandibular deficiency and open bite: journey from splinted metalloceramic prosthesis to all-ceramic crowns

This case report is of a 31-year-old female who presented with splinted and faulty metalloceramic prosthesis on maxillary anterior teeth, which was responsible for localised periodontal disease and poor aesthetics. At multiple sites the ceramic had chipped off and the prosthesis colour did not match with the adjacent healthy teeth. A multidisciplinary approach of endodontics, periodontics and prosthodontics was employed for this case. The treatment plan consisted of removing the faulty prosthesis, endodontic retreatment of inadequately root-treated teeth and endodontics in the other coronally prepared abutment teeth. Crown lengthening surgery was performed for the correction of periodontal pockets and high smile line and maintenance of an adequate biological width. After periodontal healing, all-ceramic individual crowns were placed on the maxillary anterior teeth along with a three-unit all-ceramic bridge for the replacement of the left upper maxillary first premolar. The final results were aesthetically pleasing with good marginal fit. The patient was extremely satisfied with the outcome as all her concerns were addressed. It is, therefore, advisable to consider placing individual crowns rather than multiunit splinted prosthesis whenever possible.

上顎前歯欠損にブリッジ修復を適用し審美性の回復を行った１症例

上顎前歯欠損にブリッジ修復を適用し審美性の回復を行った１症例

Computer aided manufacturing and design of fixed bridges restoring the lost dentition, soft tissue and the bone

Purpose: The aim of the paper is to present the methodology of computer aided designingand manufacturing of an all-ceramic multi-unit bridge restoring missing teeth and the lostsoft and hard tissues of the oral cavity as a result of surgical treatment of oral tumor.Design/methodology/approach: The methodology of computer aided designing andmanufacturing of the multi-unit all-ceramic bridge was presented on the basis of an actualclinical case of a patient who underwent the surgical treatment of myxoma of the oral cavity.All the steps of clinical and technical production of the bridge were described and illustrated.Findings: It is possible to use the CAD/CAM technology to design and manufactureall-ceramic multi-unit bridges restoring missing teeth and the lost soft and hard tissues ofthe oral cavity. The design of the bridge must be clinically validated using mock-ups and onlythen can be implemented for the CAM software.Practical implications: Thanks to the method of designing and manufacturing of multiunitall-ceramic bridges for patients with significant lost of the soft and hard tissues of themouth it is possible to carry out a prosthetic rehabilitation of patients after trauma and tumorsurgery.Originality/value: : The execution of extensive bridges with the maximum available heightof about 25 mm requires a high technological rigor at the design and manufacture stage. Toensure longevity of the reconstruction, it is necessary to plan all the work while maintainingthe maximum thickness of the substructure. It is desirable to provide minimum of 2 mmthick substructure and the surface of at least 20 mm2 or more in the cross-sections. At thesame time, the structure of the bridge must be supported on the alveolar ridge to provideaesthetics and endurance.

Full Contoured Tooth-Implant Supported 3-Pointic All-Ceramic Denture During Occlusal Load Transfer in Lateral Region

Abstract Implant and a tooth supported dentures are avoided by dentists because of uneven distribution of occlusal loads between a stiffer implant and a more pliable tooth. The hypothesis was that a 3-point all-ceramic bridge supported on a natural second premolar tooth and a two-pieces typical implant bears safely mastication loads. The finite element analysis showed that the implant splinted by all-ceramic zirconium bridge with the second premolar was safe under lateral mastication load, but there was found an overload at wide zone of bone tissue around the implant under the load of 800 N. The patients can safely masticate, but comminution of hard food should be avoided and they should be instructed that after such an indiscretion they need to contact a dental professional, because, in spite of integrity of the prosthesis, the bone tissue around the implant may fail and there is a hazard of intrusion of the tooth.

下顎臼歯部補綴装置の咀嚼障害に対しジルコニアフレームブリッジにより修復した症例

症例の概要：患者は初診時42歳の女性．| (4)5(6) ブリッジの咀嚼障害と審美障害を訴え来院した．通法により印象および咬合採得後，ジルコニアフレームにガラスセラミックスを加圧成型した陶材前装ブリッジをレジンセメントで装着した．約2カ月後前装陶材の一部に破折と剥離を認めたため，ブリッジを除去し，フレーム形態を再考後，再製したブリッジを装着した．装着後4年3カ月間，経過は良好であった． 考察：咬合による剪断力に対する抵抗性の付与にジルコニアフレームデザインが重要であることがわかった． 結論：ジルコニアフレームの形態を再考し，一部の咬合面を陶材前装せずジルコニアで咬合接触させることで良好な結果が得られた．

The all‐ceramic, inlay supported fixed partial denture. Part 2. Fixed partial denture design: a finite element analysis

The clinical use of all-ceramic crowns and fixed partial dentures has seen widespread adoption over the past few years due to their increasing durability and longevity. However, the application of inlays as an abutment design has not been as readily embraced because of their relatively high failure rates. With the use of an idealized inlay preparation design and prosthesis form which better distributes the tensile stresses, it is possible to utilize the inlay as support for an all-ceramic fixed partial denture. Utilizing a three-dimensional finite element analysis, a direct comparison of the inlay supported all-ceramic bridge against the traditional full crown supported all-ceramic bridge is made. The results demonstrate that peak stresses in the inlay bridge are around 20% higher than in the full crown supported bridge with von Mises peaking at about 730 MPa when subjected to theoretical average maximum bite force in the molar region of 700 N, which is similar to the ultimate tensile strengths of current zirconia based ceramics.

Zirconia-Based All-Ceramic Crowns and Bridges:Three Case Reports

The search for a clinically viable all-ceramic bridge framework has been monotonous. Until recently, few materials appear to have the necessary physical and aesthetic properties. However, the development of yttrium tetragonal zirconia polycrystals, and its adoption for use in dentistry by CAD CAM technology, may hold promise as a crown and bridge framework, this being considered suitable for single and multiple units. However, to date, no long-term clinical studies have been reported. This paper describes three cases in which zirconia frameworks were used in crowns and bridges. For the patient wishing to receive a non-metal crown or bridge, novel zirconia-based systems hold promise.